The Commonwealth of Nations, a loose confederation of nations based around the former British Empire.
Virginia, the Commonwealth of Virginia, often referring to its government.
Australia, the Commonwealth of Australia, often referring to its federal government.
The Commonwealth of England, which existed from 1649 to 1660, under Cromwell.
Kentucky, the Commonwealth of Kentucky, often referring to its government.
Massachusetts, the Commonwealth of Massachusetts, often referring to its government.
Pennsylvania, the Commonwealth of Pennsylvania, often referring to its government.
In Canada, the federal union of provinces and territories which formed Canada, beginning with New Brunswick, Nova Scotia, Ontario, and Quebec, and later including all the others.
In Canada, the date of Confederation; 1 July 1867.
In Newfoundland, the political union of Newfoundland with Canada.
In Newfoundland, the date of Confederation; 31 March 1949.